Power supply circuit and multi-phase control based on peak and average current

Abstract

According to one configuration, a multi-phase power supply adjusts a number of active phases based at least in part on a peak current supplied to a dynamic load. For example, a controller associated with the multi-phase power supply can monitor or receive a value indicative of a peak magnitude of current delivered by the multi-phase power supply to a dynamic load. The controller initiates comparison of the value to threshold information. Based at least in part on the comparison, the controller adjusts how many phases of the multi-phase power supply are activated to deliver the current delivered to the dynamic load. Thus, one embodiment herein is directed to controlling a multi-phase power supply based at least in part on a measured parameter such as peak current magnitude.

1. A method comprising:
 maintaining threshold information to include a first threshold value and a second threshold value, the first threshold value representing a peak current threshold value, the second threshold value representing a filtered current threshold value; 
 receiving a first value indicative of a peak magnitude of current delivered to a dynamic load during a window of time, the first value being a peak current value derived from multiple samples of the current taken during the window of time; 
 initiating comparison of the first value to the first threshold value of the threshold information; and 
 receiving a second value indicative of a magnitude of current delivered to the dynamic load; 
 initiating comparison of the second value to the second threshold value of the threshold information; and 
 based at least in part on the comparison, adjusting how many phases of a power supply are activated to produce the current delivered to the dynamic load; 
 responsive to detecting that the first value is less than the first threshold value and the second value is less than the second threshold value, reducing a number of phases of the power supply that are activated to produce the current delivered to the dynamic load. 
 
     
     
       2. The method as in  claim 1  further comprising:
 sampling an error voltage associated with the power supply, the error voltage representative of a voltage difference between a reference voltage and an output voltage of the power supply, the output voltage supplying the current delivered to the dynamic load; 
 comparing the error voltage to an error voltage threshold value; and 
 in response to detecting that the error voltage is above the error voltage threshold value, increasing how many phases of the power supply are activated to produce the current delivered to the dynamic load. 
 
     
     
       3. The method as in  claim 2 , wherein increasing how many phases of the power supply are activated to produce the current delivered to the dynamic load further comprises:
 activating all of the phases of the power supply to produce the current delivered to the dynamic load. 
 
     
     
       4. The method as in  claim 1  further comprising:
 enabling programming of a bandwidth associated with a low-pass filter to enable control of the power supply via custom settings; and 
 generating the second value based on repeated sampling of the current delivered to the dynamic load via the low pass filter such that the second value represents the magnitude of current delivered to the dynamic load. 
 
     
     
       5. The method as in  claim 1 , wherein adjusting how many phases of the power supply are activated includes modifying loop control feedback coefficients and current limit coefficients associated with each of the phases of the power supply that remain activated after the adjusting. 
     
     
       6. The method as in  claim 1 , wherein adjusting how many phases of the power supply are activated to produce the current delivered to the dynamic load further comprises:
 if activating additional phases in the power supply to deliver the current to the dynamic load, initiating sequential activation of multiple phases according to a predetermined activation order; and 
 if deactivating activated phases in the power supply, initiating sequential deactivation of multiple phases of the power supply in accordance with a predetermined deactivation order, the predetermined activation order being an opposite sequential ordering than the predetermined deactivation order. 
 
     
     
       7. The method as in  claim 1 , wherein adjusting how many phases of the power supply are activated to produce the current delivered to the dynamic load further comprises:
 initiating deactivation of phases in the power supply in response to detecting that i) the magnitude of the peak current delivered to the dynamic load in a respective time window is less than a peak current threshold value, and ii) a filtered current value delivered to the dynamic load is less than a filtered current threshold value. 
 
     
     
       8. The method as in  claim 1 , wherein adjusting how many phases of the power supply are activated to produce the current delivered to the dynamic load further comprises:
 initiating activation of additional phases in the power supply in response to detecting that an average current delivered to the dynamic load is greater than a threshold value. 
 
     
     
       9. The method as in  claim 1 , wherein adjusting how many phases of the power supply are activated to produce the current delivered to the dynamic load further comprises:
 initiating activation of additional phases in the power supply in response to detecting that an error voltage associated with an output of the power supply is greater than an error voltage limit. 
 
     
     
       10. The method as in  claim 1  further comprising:
 pulsing multiple phases of the power supply to deliver the current to the dynamic load; and 
 wherein adjusting how many phases of the power supply are activated to produce the current delivered to the dynamic load further comprises:
 selecting a phase of the multiple phases; and 
 initiating deactivation of the selected phase at a time when a corresponding current contribution supplied by the selected phase to the dynamic load is around zero amperes. 
 
 
     
     
       11. The method as in  claim 10 , wherein initiating deactivation of the selected phase includes disabling both a high side switch and a low side switch of the selected phase when current through a respective inductor of the selected phase is around zero amperes. 
     
     
       12. The method as in  claim 1  further comprising:
 pulsing multiple phases of the power supply to deliver the current to the dynamic load, the pulsing including cyclically switching respective high side switch circuitry and low side switch circuitry of each phase ON and OFF; and 
 wherein adjusting how many phases of the power supply are activated to produce the current delivered to the dynamic load further comprises:
 selecting a phase of the multiple phases; and 
 initiating deactivation of the selected phase at a time around a middle of a control cycle of switching respective low side switch circuitry to an ON state. 
 
 
     
     
       13. The method as in  claim 12 , wherein initiating deactivation of the selected phase includes switching both high side switch circuitry and low side switch of the selected phase to an OFF state. 
     
     
       14. The method as in  claim 1  further comprising:
 pulsing multiple phases of the power supply to deliver the current to the dynamic load; and 
 wherein adjusting how many phases of the power supply are activated to produce the current delivered to the dynamic load further comprises:
 selecting a grouping of phases from the multiple phases; and 
 initiating deactivation of the grouping of phases at a time when a corresponding net current contribution supplied by the grouping of phases to the dynamic load is around zero amperes. 
 
 
     
     
       15. The method as in  claim 1  further comprising:
 controlling multiple phases of the power supply to deliver the current to the dynamic load; 
 selecting a phase of the multiple phases; and 
 initiating deactivation of the selected phase at a respective time in a corresponding control cycle depending on an amount of current produced by the selected phase for powering the dynamic load. 
 
     
     
       16. The method as in  claim 15  further comprising:
 maintaining a phase current threshold value; 
 comparing the amount of current produced by the selected phase to the phase current threshold value; and 
 initiating deactivation of the selected phase at a different time in the corresponding control cycle depending on whether the amount of current produced by the selected phase is above the phase current threshold value. 
 
     
     
       17. The method as in  claim 16 , wherein the control cycle includes a time duration in which low side switch circuitry of the selected phase is ON and high side switch circuitry of the selected phase is OFF; and
 wherein initiating deactivation of the selected phase at a different time in the corresponding control cycle includes:
 responsive to detecting that the amount of current produced by the selected phase is below the phase current threshold value, deactivating the selected phase by switching the low side switch circuitry OFF towards an end of the time duration; and 
 responsive to detecting that the amount of current produced by the selected phase is above the phase current threshold value, deactivating the selected phase by switching the low side switch circuitry OFF around a middle of the time duration. 
 
 
     
     
       18. The method, as in  claim 1  further comprising:
 controlling multiple phases of the power supply to deliver the current to the dynamic load by activating respective high side switch circuitry of the multiple phases at different times in each control cycle of multiple control cycles; 
 selecting a group of phases of the multiple phases for deactivation; and 
 initiating deactivation of a first phase in the group of phases in a first control cycle; and 
 initiating deactivation of a second phase in the group of phases in a second control cycle subsequent to the first control cycle. 
 
     
     
       19. The method as in  claim 1 , wherein adjusting how many phases of the power supply are activated to produce the current delivered to the dynamic load further comprises:
 selecting a grouping of additional phases from the multiple phases for activation; and 
 when first activating the grouping of additional phases in a given control cycle of multiple control cycles, initiating activation of the grouping of additional phases by simultaneously activating respective high side switch circuitry of each phase in the grouping to an ON state for at least a portion of time. 
 
     
     
       20. The method as in  claim 19  further comprising:
 pulsing high side switch circuitry of at least one phase of the power supply used to deliver the current to the dynamic load prior to activating the grouping of additional phases, the pulsing including producing a control signal to turn the high side switch circuitry of the at least one phase to an ON state during a control cycle; and 
 wherein initiating activation of the grouping of additional phases further comprises:
 delaying a time of turning ON high side switch circuitry of a first phase in the grouping by a first amount relative to the control signal; and 
 delaying a time of turning ON high side switch circuitry of a second phase in the grouping by a second amount relative to the control signal. 
 
 
     
     
       21. The method as in  claim 1 , wherein the first value is a sample from the multiple samples taken during the window of time, the method further comprising:
 sampling an error voltage associated with the power supply, the error voltage representative of a voltage difference between a reference voltage and an output voltage of the power supply, the output voltage supplying the current delivered to the dynamic load; 
 comparing the error voltage to an error voltage threshold value; and 
 determining how many phases of the power supply to activate to produce the current delivered to the dynamic load based on results of:
 i) the comparison of the first value to the threshold information, 
 ii) a comparison of the second value to the second threshold value, and 
 iii) comparing the error voltage to the error voltage threshold value. 
 
 
     
     
       22. The method as in  claim 1 , wherein the first value is a sample from the multiple samples taken during the window of time. 
     
     
       23. The method as in  claim 1 , wherein the window of time is a moving window of time;
 wherein the moving window of time is a preset duration; and 
 wherein the first value represents a highest detected value of the magnitude of the current that occurs during the moving window of time. 
 
     
     
       24. The method as in  claim 23 , wherein the window of time is a most recent window of time. 
     
     
       25. A method comprising:
 sampling a power supply parameter representative of a magnitude of current supplied to a dynamic load; 
 based on multiple samples of the magnitude of current obtained from the sampling, producing a first value indicative of a peak current delivered to the dynamic load during a window of time in which the multiple samples are obtained; 
 based on sample data derived from the sampling, producing a second value indicative of an average current supplied to the dynamic load; 
 maintaining at least one threshold value defining ranges and, for each range, a corresponding number of phases of a multi-phase power supply to activate to produce the current supplied to the dynamic load; 
 initiating comparison of the first value and the second value to respective threshold values; and 
 based on results of the comparison, adjusting a number of active phases of the power supply used to produce the current supplied to the dynamic load; and responsive to detecting that the first value is less than a first threshold value and the second value is less than a second threshold value, reducing a number of phases of the power supply that are activated to produce the current delivered to the dynamic load. 
 
     
     
       26. The method as in  claim 25  further comprising:
 simultaneously implementing an efficiency control loop and a transient detection control loop in a power supply, the efficiency control loop including steps as recited in  claim 25 ; and 
 wherein implementing the transient detection control loop includes:
 sampling an error voltage associated with the power supply, the error voltage representative of a voltage difference between a reference voltage and an output voltage of the power supply, the output voltage supplying the current delivered to the dynamic load; 
 comparing the error voltage to an error voltage threshold value; and 
 in response to detecting that the error voltage is above the error voltage threshold value, increasing how many phases of the power supply are activated to produce the current delivered to the dynamic load. 
 
 
     
     
       27. The method as in  claim 25 , wherein the first value a sample from the multiple samples taken during the window of time;
 wherein the window of time is a moving window of time; 
 wherein the moving window of time is a preset duration; 
 wherein the first value represents a highest detected value of the magnitude of the current that occurs during the moving window of time; 
 wherein the window of time is a most recent window of time of continuously sampling the magnitude of the current over time.